Internal specification for a tool in the registry. Separate from the protobuf ToolSpec to avoid conflicts.
@type t() :: %Snakepit.Bridge.InternalToolSpec{ description: String.t(), exposed_to_python: boolean(), handler: (any() -> any()) | nil, metadata: map(), name: String.t(), parameters: [map()], type: :local | :remote, worker_id: String.t() | nil }